Bomper, because the British Public like to root for the underdog. Because being crap but self depreciating is seen as charming. The pairing of John and Cristina is particularly clever as he is:
old, fat, rubbish, funny and smart
while she is
a blondebombshell, buxom, an amazing dancer, and seems to adore John.
watching them is entertaing because while he is clomping about looking like an arse, she is actually putting on a really fabulous performance.
AND THEN
The judges go completely overboard with their eye rolling and terribly clever metaphores and scores of 1.
If they just said "well you did a good job" and gave him a 6 they would be in the middle of the leader board and hardly anyone would come to their rescue by voting for them and they would be OUT.
The judges only have themselves to blame They need to start doing some tactical voting themselves.